Prepare repo for automated build on Dockerhub

[bcorijn]

Changes done:

• Updated base image from Fedora to Alpine. Reduces the image size from 436MB to 130 MB.
• Moved the docker file and startup script to the root directory
• Removed the ENV variables out of the docker file and into the compose file
• Pointed the compose file to the future image on docker hub
• Adjusted the compose file to use Version 2 syntax, as recommended by Docker

This should make it doable to have an image on Dockerhub to use for people while keeping the functionality of the compose file to create a local stack.